Xcode 26 Beta 6 Sendable Build Problem

[Legoless]

How frequently does the bug occur?

Always

Description

I am using Realm 20.0.3 (latest) and had worked without any issues in Xcode 26 Beta 1. Now we're getting closer to iOS 26 release and Beta 6 does not compile our project anymore, the problem being conformance to Sendable:

Conformance of 'RLMObjectBase' to 'Sendable' is unavailable

Previously we used @unchecked Sendable on our subclasses of Realm objects, because we handled threading issues ourselves by using frozen() or similar approaches. Now Realm objects are forced to be non-Sendable and conformance cannot be added anymore - even with @unchecked. So, we need to refactor half our data layer, create adapters with same fields, which does create a lot of boilerplate. :(

So the question is, is Realm planning to implement Sendable conformance (such as: __attribute__((swift_attr("@unchecked Sendable"))), or we should start treating Realm objects differently, since they are going to create many Sendable related issues.

Stacktrace & log output

None.

Can you reproduce the bug?

Yes, every time.

Reproduction Steps

1. Create a new Project and import RealmSwift.
2. Create a Realm Model subclass: class Model : Object { }.
3. Use Model in an API that requires Sendable conformance.
4. Add @unchecked Sendable to Model:
   class Model : Object, @unchecked Sendable { ... }
5. See the error.

Version

20.0.3

What Atlas Services are you using?

Local Database only

Are you using encryption?

No

Platform OS and version(s)

iOS 26 Beta 8

Build environment

Xcode version: Xcode 26 Beta 6
Dependency manager and version: SPM

[lukaskollmer]

currently running into the same issue; did you find a workaround for this @Legoless?

what i find weird is that for me this (marking a realm-managed class as @unchecked Sendable) works fine in a new project, but doing the same in my already-existing xcode project causes a ton of compilation issues, despite both projects using the same build settings for all swift-related options...

[Legoless]

@lukaskollmer I tried using adapters, but caused many issues since our structure has a lot of references that need to be resolved for everything to work. For now, I could get things to compile by adding an extension in our model layer package:

extension Object: @unchecked @retroactive Sendable {
    
}